Nine Layers of the Edible Forest Garden (Food Forest)

Food Forests have been around for thousands of years in tropical and sub-tropical climates. In fact, there is a Food Forest currently still producing food in Morocco that was established 2,000 years ago! The concept of food forestry was almost lost to the annals of history when Robert Hart decided to adapt this design to his temperate climate in the UK in the 1960’s. The idea of a Forest Garden was brought to the public’s awareness when Robert wrote a book documenting his grand experiment. Bill Mollison, the co-founder of Permaculture, visited Robert’s site in 1990, and he quickly adopted this design element into his teachings and work. Initially, when Robert Hart described the layers of the Forest Garden, I believe he did so based on what he had and what he studied. Since then, Robert Hart’s categorization of the layers of the Forest Garden has stood unquestioned.

Until now.

I am not actually arguing about the existing layers. My issue is that there are certain layers that have been ignored or overlooked. My goal is to resolve this discrepancy today. As you can see in my illustration above, I believe that there are 9 layers in a Forest Garden. The first 7 are identical to Robert Hart’s initial design. The missing layers are the Aquatic or Wetland Layer and the Mycelial or Fungus Layer.

Here are my Nine Layers of the Edible Forest Garden:

Canopy/Tall Tree Layer

Sub-Canopy/Large Shrub Layer

Shrub Layer

Herbaceous Layer

Groundcover/Creeper Layer

Underground Layer

Vertical/Climber Layer

Aquatic/Wetland Layer

Mycelial/Fungal Layer

1. Canopy or Tall Tree LayerTypically over 30 feet (~9 meters) high. This layer is for larger Forest Gardens. Timber trees, large nut trees, and nitrogen-fixing trees are the typical trees in this category. There are a number of larger fruiting trees that can be used here as well depending on the species, varieties, and rootstocks used.

2. Sub-Canopy/Large Shrub LayerTypically 10-30 feet (3-9 meters) high. In most Forest Gardens, or at least those with limited space, these plants often make up the acting Canopy layer. The majority of fruit trees fall into this layer.

3. Shrub LayerTypically up to 10 feet (3 meters) high. The majority of fruiting bushes fall into this layer. Includes many nut, flowering, medicinal, and other beneficial plants as well.

4. Herbaceous LayerPlants in this layer die back to the ground every winter… if winters are cold enough, that is. They do not produce woody stems as the Shrub layer does. Many cullinary and medicinal herbs are in this layer. A large variety of other beneficial plants fall into this layer.

5. Groundcover/Creeper LayerThere is some overlap with the Herbaceous layer and the Groundcover layer; however plants in this layer are often shade tolerant, grow much closer to the ground, grow densely to fill bare patches of soil, and often can tolerate some foot traffic.

6. Underground LayerThese are root crops. There are an amazing variety of edible roots that most people have never heard of. Many of these plants can be utilized in the Herbaceous Layer, the Vining/Climbing Layer, and the Groundcover/Creeper Layer.

7. Vertical/Climber LayerThese vining and climbing plants span multiple layers depending on how they are trained or what they climb all on their own. They are a great way to add more productivity to a small space, but be warned. Trying to pick grapes that have climbed up a 60 foot Walnut Tree can be interesting to say the least.

8. Aquatic/Wetland LayerThis is my first new layer to the Forest Garden. Some will say that a forest doesn’t grow in the water, so this layer is inappropriate for the Forest Garden. I disagree. Many forests have streams flowing through or ponds in the center. There are a whole host of plants that thrive in wetlands or at the water’s edge. There are many plants that grow only in water. To ignore this large list of plants is to leave out many useful species that provide food, fiber, medicinals, animal feed, wildlife food and habitat, compost, biomass, and maybe most important, water filtration through bioremediation (or phytoremediation). We are intentionally designing Forest Gardens which incorporate water features, and it is time we add the Aquatic/Wetland Layer to the lexicon.

9. Mycelial/Fungal LayerThis is my second new layer to the Forest Garden. Fungal networks live in healthy soils. They will live on, and even within, the roots of plants in the Forest Garden. This underground fungal network transports nutrients and moisture from one area of the forest to another depending on the needs of the plants. It is an amazing system which we are only just beginning to comprehend. As more and more research is being conducted on how mycelium help build and maintain forests, it is shocking that this layer has not yet been added to the list. In addition to the vital work this layer contributes to developing and maintaining the forest, it will even provide mushrooms from time to time that we can utilize for food and medicine. If we are more proactive, we can cultivate this layer intentionally and dramatically increase our harvest.UPDATE: I have received numerous comments and questions about this layer. I wrote a more detailed description and defense of this layer here.

So this is my proposal to the Permaculture world. Let’s consider all nine layers when designing our Forest Gardens.

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14 Comments

Hi John,
I think it is sensible to include those two very important parts of our ecosystems. Wetlands are vital in processing nutrient runoff and are very productive in their own right. However, on consideration, within an aquatic system, there are also a number of layers, and very different types of systems. There are the differing “layers” along the light gradient from very bright on the surface of the water down to low light, very similar to the layers in a forest, for example. Another example are the differences between stream, pond and swampland ecosystems, and the edge effects that occur between them.
And as for the layer under the ground – I absolutely agree with you that it needs to be included – I would suggest though, that it be called something like “Under Soil Surface” or “Microorganism” layer, because the bacteria, archaea, worms, protozoa, and many other organisms, and their inter relationships, are all as important as the fungi/hyphae that are in the soil.
Regards Richard

Well done John, I completely agree. I am surprised that these have not been included already in some manner. There is so much that can be included in the aquatic/wetland layer I am surprised this was left out in the first place.

As long as we are working outside the Plantae kingdom (which is fine by me), what do you think of adding bacterial to the Mycelial/Fungal layer classification? Or maybe calling this the Sub-soil/Decomposer layer; as bacteria and fungi could also exist in water but not necessarily be a part of this layer. This more general name could also be utilized to include other things like worms and larger decomposers.

These are just thoughts that pop into my mind as I try to consider this layer in a design system. I will be thinking about more than just the fungi.

Well, I agree in part and disagree in part… were I disagree is that these layers have been overlooked 🙂
See the work of Martin Crawford at the Agroforestry Research Trust – specifically his wondrous tome ‘Creating A Forest Garden’ (available via Amazon, of course, including a ‘Look inside’ page). He covers quite a range of aquatics and is very keen on mycorrhizal associates and fungal crops, though he treats these as elements of the ‘underground’ layer. But I do see value in labelling this a separate layer, as you have done, because it’s such a big contribution to the overall health of the system and it could be easy to overlook otherwise.
As for ponds, they have more to contribute than purely being a home for aquatics; they are also great for modifying microclimate (humidity and light reflection) and provide habitat for extra insect species (but beware dragonflies are big bee predators, so if you have a hive multiple small ponds are safer than one larger one).

I do agree that those two elements are overlooked by too many people, but on the whole I’m not an advocate of the layer concept. What is a grape? Leave it unsupported and it grows somewhat shrublike. Grow it up a wall its a vine/creeper. Grow it over a gazebo and it becomes a canopy. Its a good teaching tool for beginners but a bit too limiting for my liking.

If I was to add another overlooked layer I would nominate the leaf-litter layer. Once you have a leaf litter layer you know you have a healthy ecosystem. Its home to most of the initial decomposers, provides shelter for lizards, frogs etc.. Personally I don’t eat snails but technically they are a food product of this layer. So theres a tenth layer for you. You could get all biblical and call them the ten commandments of permaculture “Thou shalt grow a canopy of tall trees” etc.

Dan – While I understand your point, I rather disagree. It is significantly more than just a teaching tool for beginners. It is actually a vital part of design. I think you are looking at this a bit backwards. It is not just about the design element (its intrinsic nature), but how we choose to manage an element that determines where it belongs in the design. A tree can be a dwarf, semi-dwarf, or full-sized. It can be coppiced or pollarded or allowed to grow to its natural height with or without pruning. This is similar to the grape you are talking about, but when we are talking about design, it is about how, where, and when we place that element in the system, and how it will be managed in the system, that determines its function. And the function determines the layer in which the element belongs.

We must have a structure or model in which to develop a mainframe design. With a food forest, our structure is the concept of layers. If we abandon that structure we will end up with errors in our design. We will have trees planted too close togther. We will have sun-loving trees sitting unproductive in deep shade. We will have shade-thriving shrubs burning in the sun. We will have vining plants choking out or breaking branches of small trees and shrubs.

I have come across too many people (and I am not really talking about Dan now) who call themselves Permaculturists who want to abandon the science of design and just see how things “feel”. I think there is some benefit to that, but we must be careful. This is a great way to create type 1 errors in our design. This is a great way to minimize production on our land. This is a great way to make more work for ourselves.

Now, as far as the leaf litter. This is a part of the soil really, but it is not there yet. We are not designing this layer – it occurs when we do everything else right. And mostly, we just let it be. There is no significant management or maintenance that we do to this layer. There is almost no harvest (food, fuel, fiber, medicines, etc.) from this layer… maybe snails or other transients. It is vital, but not something we actively manage. Hence, not a layer in my designs.

Well, I am inline with the philosophy of Fukuoka. The point of an ideal permaculture system is that needs little or no management. If you have to control how things grow to that degree, to my mind you’re still using conventional agricultural thought. I dislike that many people who consider themselves permaculturists still tend to think this way but it is deeply engrained in western culture.

I would recommend reading the one straw revolution, which was written about thirty years before the word permaculture was even coined.

The central truth is that nature designs better systems than man. Throw out a hundred seeds and trees will grow where and how they want, not where and how you think they should. I have never planted a single fruit tree, yet I harvest a couple hundred kilos of fruit per year from my small block. I don’t water or fertilise them, I just let them do their thing. Doubtless there are other people who get higher yields per area than I, but in terms of effort vs reward I am way out in front.

Reminds me of some things I was told about chess. When I was young many people said to me “Its good to learn chess because it teaches you to think strategically”, but when I was a bit older I met a wise man who said “Its bad to learn chess because it locks you into one way of thought, linear, thinking in boxes”.

Dan – I think there are two approaches to this. The first is to be a forager… eat off the land. If you are fortunate to be in an area that is abundant, than you can (as you do) harvest what nature provides. The problem with that is that few people have this. Yes, it is the ideal. Yes, it is how is potentially should be. Yes, if we all would let nature heal itself, then we would end up with this eventually. However, that is NOT how it is now. Also, while you may be able to harvest a lot of fruit, are you able to survive on this alone? And before you say, “Yes, of course”, how long have you actually done it? I come across people all the time who tell me that they could live off the wild, and they can, for a few days. But what about for a week, a month, a year… all year round, through all the seasons. What if everyone in your area decided to do the same thing? Would your area support your entire community without planting any additional fruit trees or nut trees or raising livestock or doing any management at all?

This is where the second approach comes to play. We purposely design systems to produce what we need, when we need it, and when we can use it. This is working WITH nature, not against it. We are being intentional about our design to meet ALL our needs, and a well-designed Forest Garden can meet almost all our needs. Truly it can. We can have year-round food, fiber, fuel, medicines, shelter, and primary or value-added products we can sell on top of it to earn an income.

A forager could also get all of this without ever planting a tree, as you have said. But it will take a LOT more area to do this. Most people are not living in areas where they have access to enough land to truly support all their needs from the wild. Most places in the world do not have a natural congregation of extremely useful plants. Some do, but most do not. And many of the ones that do were actually placed there, or encouraged (given advantage) by indigenous peoples. It looks so “natural” that European settlers did not recognize them as such.

In addition, one thing I do not understand. Why is it that people always personify nature and separate humans from it? We humans are part of nature. We are part of the Earth and part of the natural world. We are just one of millions of creatures/species that live and die here. We are not separated from nature. Humans do have the ability to devastate ecosystems, but we also have the ability to regenerate ecosystems.

The bottom line is that I feel it is vital to work with nature, since we are part of nature itself, to design systems that regenerate and build resilient systems that optimize the products of the natural world, of which we can benefit, yet still allows nature to thrive.

I totally agree with you on that. I was just studying a PC book which talked about the 7 layers but I was missing the fungal layer as the eighth one. So I went onto the Internet for a search and found your site. And saw that you even mentioned algae as another layer. Yes! That makes a lot of sense. Even more so when you know that production in water outproduces land 30 – 50 times! The only thing is I would put algae is the ninth layer not the eighth.

In that sense it makes sense to include also a pond as part of a food forest as it does increase diversity and edges and increases functionality manifold : )

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